Proportional dividers.



No. 896,614. PATENTED AUG.18, 1908. G. H. BENEDICT.

PROPORTIONAL DIVIDERS.

APPLICATION FILED 313.28, 1908.

' same proportion.

GEORGE H. BENEDICT, OF CHICAGO, ILLINCZEB.

raorois'rronar. DIviDEas.

Specification of Letters Patent. 1?

Application filed February 28, 1908. Serial Ni). i 3,312.

To all whom it may concern:

Be it known thatI, GEORGE H. BENEDICT, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain, new and useful Improvements in Proportional Dividers,ofwhich the following is a full, clear, and exact specification. y

This invention relates more particularly to a proportional divider inthe form of a chart for determining theproportion of reduction of anygiven size to another given size or, where the proportion of reductionan d"the original .size are previously ascertained or given, todetermining what the reduced size will be when the original is reducedin that proportion, and the invention has for its primary object toprovide a proportional divider or chart by which any or all of theseresults may be readily ascertained.

lhe invention may of course be used for calculations of this characterin all computations where such calculations are re uired, but it will befound especially: userul for phpto-cngravers or photo-lithographers inquickly determining the proportion of reduction to be made in thephotograph of an original copy when the size of the photograph is given;or determining the size of the photo' graph to be made when theproportion'of reduction is previously known. It is of course understoodin the art of photo lithography that a camera, while adjusted tophotograph an original down to a certain proportion of reduct-itm,cannot be used while thus adjusted for photographing any other articledown to a different proportion of reduction. It is frequently the case,however, that the photographer will have a great variety of copies orarticles to be photographed, and these will vary in size andconsequently cannot all be photographed upon the same plate, or with thecamera set at the same focus and adjustment, unless it be previouslyascertained-that they are all to be reduced in the For example, it mightbe required to reduce a copy three feet long to a photograih one footlong, which would be two-thir s reduction, and it may also be requiredto reduce a copy three inches long to a one-third reduction. If thesetwo copies are placed before the camera at one time, it is obvious thatwhen the camera is positioned to reduce the larger one two feet, thesmaller one would bev reduced to one inch instead of two inches.Consequently, these two artiseparately. however, that both articles areto he reduced cles must be photographed at ditlerent' times,

and the camera must be adjusted for each If be ascertained in advance,

two-thirds, or the same proportion ofreduction, they may be photographedat the same time and upon the same plate without regard to the greatdisparityin their original sizes, and this would be true with any numberof original copies, there being no limit to the number that might bephotographed atone timewithin thecapacity of the negative plate. in thisart, however, the customer does not always give the proportion ofreduction, hut more often simply requires a copy of a given size to hereduced to a certain size stated in inches, or other measure nent, andconsequently, where the photographer has a great variety of copiesvarying in size to be reduced to a great variety of ot ier sizes, itbecomes necessary for him to calculate on each one the exact proportionof reduction which each is to undergo in order to ascertain the exactreduced size required by the customer, or else it would he necessary tophotograph each article separately and. adjust the camera until theimage therein is brought down to the re quired' size and is sharplyfocused on the camera screen. Needless to say, such a method is not onlytroublesome and tedious, but consumes valuable time and entails a greatwaste of space on plates that are ordinarily large enough for more thanone photograph, to say nothing of the extra expendi ture of light andchemicals in the development of these plates. With a chart such thatembodying this invention, hovi ever, the exact proportion of reductionof all these various copies may he readily ascertained and theproportion marked thereon, and all those of the same proportion maybegrouped together to be photographed at a single exposure or by a singleadjustment of the camera and its lens or, by providing the camera indexslide with a scale of figures or characters corresponding to a similarscale of figures or characters on the chart constituting this invention,the user of the chart may accomplish the same object by merely makingthese numbers or characters on the backs of the copies to indicate tothe photographer that all copies of a given number or character may bephotographed at a single exposure, or with the camera at the sameadjustment.

With a view to the attainment of these ends and the accomplishment ofcertain other objects which will hereinafter appear, the inventionconsists in the features of n'ovelty which will now be described withreference to the accompanying drawing, and then more particularlypointed out in the claims.

The said drawing is a face View of a proportional divider in the form ofa chart embodying this invention. Upon a sheet of cardboard, paper, orother suitable surface is printed or indicated points extending betweenthe. lines A-D, indicating linear measurement, and may be suitablydivided into units of measurement, and fractions of such units.

In the exemplification shown in the drawing, the units of measurementindicated in this scale A-D, are inches, and it will be seen that it isdivided into eight equal parts along the line AD, by the numerals 1 to8. Extending at an angle to the line AD is a line AB', and on one sideof this line A-.B is another scale divided into units of linearmeasurement and fractions of such units. The two scales Al3 and A.Dstart from a common point and they are correspondingly divided and.sub-divided. That is to say, the scale A- J being divided into inches,the other scale A-B is also divided into inches, and the fractionaldivisions of one of these scales are equal to the fractional divisionsof the other of these scales. The highest number of the scale A-B,however, is situated contiguous the lowest number of the scale Al). Inthis exemplification of the inven tion, the two scales A-B and A-l) arear ranged at right angles to each other in such a way that if thcy wcrcof the same length and their outer ends were connected together, theywould constitute a triang e, but in order to save width, it will beseenthat the length coi'istituting the difference between the length. oi theline'A-B and the length of-the line A-D is added to the scale A- l) by avertical line (.---D. The height of the line C l) is si'ich that it thelines A-B and AD were of equal length and connected together bycontinuation of the line B O, the line CD would intersect the line BU.

From. the divisions or graduations of the scale AB are extended parallelhorizontal lines which. preferably continue entirely across the chart,and from the graduations and numerals of the scale AD are continuedparallel perpendicular lines which cross the said paral el linesextending from the graduations of the scale AB and form perfect squarestherewith. In thus dividing the chart into squares, it is preferable toindicate the graduations of the whole numbers by heavy lines, and thoseof the fractional divisions by light lines. in this example of theinvention, the fractional divisions are uartcr inches, and for thepurpose which will be presently described. the fractional divisions ofthe scale AB are numbered consecutively, and consequently, in a twelveinch scale, these numbers will ran e from 1 to 18. These numbersindicating the fractions of scale A-B, however, are arranged in thereverse order to those indicating the whole inches.

In addition to the lines dividing the chart into squares, it'is alsoprovided with radial lines which extend from the apex of the lines A Eand B-C to the graduations or divisions and sub-divisions of the scaleADC.

The scale A--DO is for indicating the size for reduction or enlargementand also the size of the copy. Thus, for example, if it should bedesired to reduce a copy from ilinches X 7-} inches to 5!,- inches, thediagonal line extending from the point or graduation on the scale A-Dindicating the length of the copy, or 7 inches, will be followed to thepoint where it intersects the perpendicular line extending from thepoint on the scale A-D, which indicates the length of the reduced size,which is 5; inches, and from this point, that is, the point ofintersection of the said two lines, the nearest horizontal line isfollowed to-thc left, and the number in the scale AB is indicated. Inthis example of the invention, the number in the scale A-B thusindicated is 14. Now, it is obvious that if the camera slide be providedwith an index corresponding to the photographers focusing indexindicated on the chart along the line AB b T the numbers 1 to 48, thephotographer will be able to instantly determine that the camera must bemoved along the slide until its pointer registers with the number 14,when it will be in exact position for photographing a copy inches longdown to a reduced size of 5} inches long. It is unnecessary that thephotographer know just what proportion of reduction this would amountto, but it desired the proportion of reduction may be indicated on theleft of the line A B contiguous to the number 14. In the example giventhis would be about 3/10ths reduc tion. In this cxempliiication of theinvention, these proportions of reduction are not indicated at the endof each of the horizontal lines because it is unnecessary in )racticc,but the proportions of teduction which are usually required areindicated in a separate scale at the left of the line AB and at the mintin the length thereof where they would tall if horizontal lines weredrawn from the diagonal lines to the line AB at the point Where thediagonal lines indicating the length of the copy intersect the verticallines indicating the length of the reduced sizes. It will be seen thatthese fractions do not always fall at the particular horizontal linesindicating quarter inches, but the y are near enough for practicalurioses, and it is not desirable to provide t is dhart with the addiLoner nvmLrwLE CDPY rxtent of enlargement.

acacia ti onal horizontal lines extending from the fractions indicatingthe proportion of reduction, as such a multiplicity of lines would beconfusing.

Should it he desired to ascertain the exact width of the reduction, thediagonal line on the scale AD is followed until it intersects ahorizontal line extending from 'the proportion oi reduction which inthis example would he 3/l0ths. There being no horizontal line indicatedat this point, it must be imagined or indicated by a straight edge. Thepoint or graduation on the scale AD directly below the point where thisimaginary line touches the diagonal line will be the width of thereduction, which in this example is about 3 3/16ths inches.

F or cimvenience in the use of the chart, and as a guide to the eye, astring E may be suspended from the apex of the lines A-B and 3-4), whichwill guide the eye along the diagonal lines, and may also serve forindicating intermediate positions between these lines. 1

Should it he desired to use the chart for calculating enlargements, thesame may he provided on the right hand side with a series ol numeralsstarting at the mid-length of that side olthc triangle and continuing tothe lower righthand corner from 1 to 24, the horizontal lines spacedone-fourth inch apart heing thus numhered consecutively, and opposite oradjacent each ol' these consecutive numhers is placed a fractionindicating the The middle one of the horizontal lines, the, the. oneextending iron; the numeral 6, is made heavier than the other horizontallines, so as to readily distinguish that one lrom the others, and thedivisions lhcrcol produced hy the heavy vertical lines are numhcrcd.lromlclt to right consoculivcly l'rom l to (i. This heavy horizonlalline is to he ulilizcd for measuring the cop to he enlarged;

in using the chart l'or enlarging a copy from a 4", inch slzc to 6; inchsize, for example, the indicating string is placed upon the poinlrepresenting 4,} inches on the heavy horizontal line, and is thenfollowed downward lo the point where it crosses the. Vertical lincindicating the size ol the. enlargement. or (it inchcs. The horizontalline ncnl'csl this point of intersection when lollowcd towards theright, will give the proportion ol enlargement. in this example, suchhorizontal lino leads to the fraction .l/fis'lhs, which is thcproportion of enlargement ol' a copy 4: to ill.

\ow, il is quite cvidcnt that by providing the camera slide with a setof numerals corresponding to the numerals extending from the heavyhorizontal line downwardly on the right of the chart, that is, thenumerals from 1 to :24, it may be told at a glance just Where the cameraslide should be adjusted in order to effect this enlargement. In theparticu lar example given, it will be seen that the horizontal lineadjacent the fraction 3/8ths leads to the numeral 9, and conse uentlythe photographer understands that LlS camera must he adjusted on theslide to the numeral 9, which will produce a photograph 3/8ths largerthan a copy originally measuring 4-}. It is of course understood thatthe numerals on a camera stand or slide corresponding to the numerals 1to 24 must be accurately placed, but when once the camera has beenadjusted for these various positions and the. posit-ions marked, itsuffices for all time so long as the same lens is employed.

In order that the invention may be understood by those skilled in theart, the details of an eXemplilication thereof have been thusspecifically described, but

Vi hat I claim is In a device for the purpose described, the combinationof a scale divided into fractions of a unit of measurement, linesextending from said divisions,'a second scale converging with said firstscale and being'similarly divided, lines extending from the divisions ofthe second scale and crossing the lines 01' the. first scale and formingsquares therewith, means for indicating a straight line between a commonpoint at the outer end of the first said scale to any one of thedivisions of the second said scale, and a scale indicating proportionsof reduction arranged contiguous to said first scale and containingfractional noiations, each of said fractional notations heing located.in the third said scale at a point inthe length of the first said scalewhere the first said scale would he cut by a right line. which wouldintersect a line drawn fromv said common point of radiation to the pointon the second said scale indicating the size to he rcduced,.and a thirdline intersecting the last said. line and the second said scale at thepoint onthc second said scale indicating the size ol',thc reduction.

In testimony whereof I have signed my name to this specification, in thepresence ol' two suhscrihing witnesses, on this 20th. day of Fchruary A.l), 1908.

GEO. ll. lilCNlCDlC'l. VVi ti losses W. ll. Dn BUSH,

